[sdiy] Bending a Sum

[Tom Wiltshire]

Hi Tom,

If the blue line was the other way up, it'd be a soft-knee compression curve, or a soft distortion. Perhaps you could experiment with some of the typical soft distortion circuits, and then invert the output to get their output to apparently clip heading towards zero volts instead of towards 5V. Alternatively use the soft clipping on the negative half of the waveform and then shift it up I suppose.

I've only tried straightening out the 2164 in software myself, so these ideas are untested.

HTH,
Tom

On 18 Nov 2013, at 13:29, Tom Bugs <admin at bugbrand.co.uk> wrote:

> Just wondered if anyone may have a brainwave on this little problem...
> 
> It is around the area of linearizing the response of an SSM2164 - but, at the moment (blah blah) I wanted to see if I can achieve a rough linearization WITHOUT using the well documented Irwin EDM technique.
> 
> http://bugbrand.co.uk/images/SumBend.jpg
> 
> I just have a simple opamp sum stage to generate 5V to 0V from a 0V to 10V control - that's the green line.
> The standard linearization technique achieves the blue line.
> How could I bend green to blue without too much extra complexity and, crucially, without using another 2164 cell?
> 
> Thanks!Tom
> 
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